Gigantomastia or “Gravidic macromastia” during pregnancy is a massive diffuse enlargement of the breast during gestational period. It is a rare condition of undetermined aetiology, which may be due to hormonal excess, or hypersensitivity of the target organ to normal hormonal level. Histologically it is due to glandular hyperplasia with an increase in connective tissue. This paper reports an unusual case of gigantomastia in 22 years old lady, who is gravida 2, para nil, with total breast weight of 15,850 kg. Ulceration and haemorrhage of the breasts complicated the picture and end in abortion followed by subtotal mastectomy and free implantation of nipple areola complex.